Cisco Catalyst 4500 Series, Software Configuration Manual

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 46 Configuring Voice Interfaces
Configuring a Port to Connect to a Cisco 7960 IP Phone
Figure 46-1 Cisco 7960 IP Phone Connected to a Catalyst 4500 Series Switch
Cisco IP Phone Voice Traffic
You can configure an access port with an attached Cisco IP phone to use one VLAN for voice traffic and
another VLAN for data traffic from a device attached to the phone. You can configure access ports on
the switch to send Cisco Discovery Protocol (CDP) packets that instruct an attached phone to send voice
traffic to the switch in any of these ways:
•
In the voice VLAN tagged with a Layer 2 CoS priority value
•
In the access VLAN tagged with a Layer 2 CoS priority value
•
In the access VLAN, untagged (no Layer 2 CoS priority value)
Note
In all configurations, the voice traffic carries a Layer 3 IP precedence value (the default is 5 for voice
traffic and 3 for voice control traffic).
Cisco IP Phone Data Traffic
The switch can also process tagged data traffic (traffic in IEEE 802.1Q or IEEE 802.1p frame types) from
the device attached to the access port on the Cisco IP phone. See
Figure 46-1 . You can configure Layer 2
access ports on the switch to send CDP packets that instruct the attached phone to configure the phone
access port in one of these modes:
•
In trusted mode, all traffic received using the access port on the Cisco IP phone passes using the
phone unchanged.
•
In untrusted mode, all traffic in IEEE 802.1Q or IEEE 802.1p frames received using the access port
on the Cisco IP phone receive a configured Layer 2 CoS value. The default Layer 2 CoS value is 0.
Untrusted mode is the default.
Note Untagged traffic from the device attached to the Cisco IP phone passes using the phone unchanged,
regardless of the trust state of the access port on the phone.
Configuring a Port to Connect to a Cisco 7960 IP Phone
Because a Cisco 7960 IP Phone also supports connection to a PC or another device, an interface
connecting a Catalyst 4500 series switch to a Cisco 7960 IP Phone can carry a mix of voice and data
traffic.
The three configurations for a port connected to a Cisco 7960 IP Phone are as follows:
• All traffic is transmitted according to the default CoS priority of the port. it is the default.
IP Phone
Catalyst 4500 Series Switch
PC
105247
IP